Poor retention in medical care is one of the primary reasons people die of HIV/AIDS today. Modern HIV treatment has transformed this deadly infection into a treatable chronic condition. There are no proven interventions to better retain people in HIV primary care. Hospitalized patients with HIV infection are at high risk for poor retention in care. A single or dual session intervention is essential for most patients out of care, because any patient who could be recruited into a multi-session intervention could likely be recruited back into primary care. Our team has been researching retention in HIV care for over 7 years. Using the information-motivation-behavioral skills model as a framework, our data indicate that among patients recently diagnosed with HIV infection, access to HIV primary care is affected by critical information gaps regarding the availability of care and treatment, limited motivation related to poor coping strategies and low trust in the healthcare system, and weak behavior skills reflected in low self-efficacy and social support around adherence to HIV care. These factors result in poor ability to navigate the health care system and remain in HIV care. We have developed a structured, theory-based, Patient Mentor Program. The Patient Mentor Program was developed to improve retention into HIV primary care by increasing patient knowledge about HIV and the care system, increasing self-efficacy, and promoting active self-management. In a one- time interaction at the Thomas Street Health Center, volunteer patient mentors greet new patients who are arriving for their intake visit to the clinic, guide them through the intake visit and support them. In our preliminary, quasi-experimental data, 88% of patients who had a patient mentor during that intake visit completed a physician visit within the next 90 days, compared to 78% of patients who did not have a mentor (p<.001). These effects remained significant after adjusting for baseline demographic and clinical characteristics, and persisted into the 90-180 day interval after intake. We will test the efficacy of the TSHC patient mentor intervention in a 5-year randomized, controlled trial in 434 socio-economically and racially diverse HIV-infected patients hospitalized at Ben Taub General Hospital. We hypothesize that the intervention will meaningfully increase retention in HIV primary care after discharge compared to an attention control. Our Specific Aims are: 1) To test the efficacy of the patient mentor intervention on retention in HIV primary care after hospital discharge; 2) To test the efficacy of a patient mentor intervention on secondary outcomes that include health services use, health-related quality of life, and clinical outcomes; 3) To determine the mediating factors associated with response to the intervention, and the individual and system facilitators and barriers to retention in HIV primary care. This study addresses one of the most important challenges in HIV care today, i.e., expanding modern HIV treatment to all those in need, and may also impact race-based disparities in the health of people with HIV infection.